1. Field of the Invention
The present invention relates to an image analysis device and method and a recording medium having a program which analyze a captured radiographic image of a subject.
2. Description of the Related Art
When a radiographic image of a subject is captured by radiation passing through the subject, the influence of the scattering of radiation or a reduction in the transmissivity of radiation in the subject increases as the thickness of the subject increases, which results in a change in the quality of the acquired radiographic image.
In order to respond to the above-mentioned problem, a technique has been proposed which roughly estimates the thickness of the subject, on the basis of various kinds of information, such as imaging conditions, a signal value of a radiographic image, the histogram width of the signal value of the radiographic image, and the length of the subject in the subject image in a predetermined direction, and changes the conditions of image processing, such as a process of removing scattered X-rays of the captured radiographic image, or the imaging conditions applied to the capture of the radiographic image, on the basis of the estimated thickness of the subject.
For example, WO2007/114470A discloses a technique which generates a simulation image for determining appropriate imaging conditions corresponding to the thickness data of the human body and uses a representative thickness of an imaging target part which is measured from a computed tomography image (CT image) as the body thickness of the subject.